Circuitry for generating a stable reference frequency as well as circuitry for phase-aligning digital signals conventionally uses a feedback loop that includes a phase comparator and charge pump. The charge pump generates a current or other control signal based on a phase difference between two input signals. One issue with these conventional circuits is that internal mismatches, parasitics and noise, among other things, may cause non-linearities and skew the output due to charge injection in the charge pump, particularly when the phase approaches zero.